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Laser Technology
Saturday | 01 April, 2006 | 4:34 am

From weeks to hours

By Lincoln Brunner

The latest in lasers' growing list of useful applications: helping you fit soda cans in your fridge.

It was summer 2005, and bottling companies for a large soft-drink maker across the country had one of those very good problems: the wildly popular refrigerator pack.

The refrigerator pack's two-high, six-deep configuration had proven utterly convenient for customers since the concept was introduced four years before and utterly inconvenient for the bottlers' conveying systems. The conveying systems had problems handling the long boxes one at a time, so the soft-drink maker turned to Pearson Packaging Systems for a solution.

Pearson, a manufacturer of custom packaging equipment, came up with a prototype machine that stuck two refrigerator packs together for a short time, alleviating the palletizing and conveying issues that had gummed up production. The company liked the prototype so much, it ordered more--68 more, to be exact. In 75 days.

Enter Pearson's laser, a 4-kilowatt Amada FO3015. Installed in July 2002, the FO3015 allowed Pearson to say a quick "yes" to a task that, pre-laser, would have been like trying to build a space shuttle.

"We wouldn't have been able to do it [in-house]," says Dave Fode, facility supervisor at Pearson's plant in Spokane, Wash. "We would have had to contract with an outside vendor to do it for us, most likely somebody with a laser."

The FO3015 laser works in a cell alongside an 88-ton Amada FDB press brake using precision-ground, segmented Amada tooling. Using the cell, Pearson met the soft-drink company's deadline by building a kit every night during the swing shift, complete with all the machined and lathed parts, ready to go for the assembly crew the following morning. Next night, repeat process.

"We rapid-fired a machine a day off that line," Fode says. "We actually exceeded the company's expectations on that."

Laser equals lean
That rapid-fire, do-it-now concept has come to govern Pearson's entire MO, a lean manufacturing mindset that revolves around the laser cell. Where Pearson once required up to a third of its factory floor for storage, it now only brings in what it needs right away.

Pearson begins the day with the parts that require the most routing stops--for example, laser, press brake, milling machine and lathe--and works its way down to simpler parts throughout the day. To avoid cutting parts even a half-day ahead, Pearson staggered its shifts so that the laser supplies flat parts just in time to be used.

"The laser cuts today what manufacturing needs today," Fode says. "We don't go a day ahead. We don't go half a day ahead.

"We might actually do more setups than a normal shop. We might throw 1/4-inch, hot-roll sheet up there two or three times in the same day rather than just throw it up there once and cut everything we need. We don't do that. We throw it up there, cut what is needed now. Then we take that off and we'll get to the next group of parts that have fewer routing stops. Toward the end of the day, the stuff that's just going from the laser to the brake and then to the paint shop is done last."

Treating a laser, or any equipment, like a monument is anathema to the gurus of lean. However, incorporating more setup times and using the laser on an as-needed basis keeps the shop from creating a bottleneck at the Amada cell.

"You can turn a drill press into a monument if you overload it," Fode says. "It's all how you schedule work through the machine."

Lower lead times, lower costs
Pearson knows all about how to overload a machine. Before purchasing the Amada cell, the company had relied on a waterjet to cut its flat parts since 1996. Pearson found the technology reliable and accurate, but the maintenance time and backlog started to take its toll. However, it wasn't time lost, just a step toward what the business ultimately needed for its carbon and stainless work.

"It made a big difference for us," Fode says. "It got us into doing more sheet metal, taking lots of large weldments and turning them into big folded pans. Bringing that technology into the shop, we proved that unleashing engineering with the ability to make folded sheet metal parts rather than these big weldments really cut down on the labor going into a lot of these newer parts."

That move from weldments to bent sheet metal only intensified after the laser and press brake arrived. Today Pearson's engineers design their parts with the laser in mind from the first click of the mouse. Doug Slye, the Amada laser automation consultant that Pearson worked with on the installation, notes that in certain cases, Pearson engineers now can go from design concept to finished part within hours--instead of days or weeks.

"There was a lot of structural subframe that was built into the machine before--a lot of tubing, a lot of angle iron, a lot of flat bar," Slye says. "That had to be cut-to-length, sawed, notched and machined. When they went to the laser, they discovered that the flexibility of the machine allowed them to re-engineer a lot of their products. It took a lot of the angle iron and tube out of the product and reduced their lead times from weeks to days."

Fode notes that the laser-brake cell has pulled complexity out of the production process by allowing Pearson to:

  • Cut odd features into parts that can accept hex components.
  • Cut bolt-hole patterns with no calculations other than programming.
  • Bolt components onto brackets to move on rather than welding and laminating them.
  • Fabricate frames from 11-gauge steel rather than using welded tube frames.
  • Notch the sheet metal to show welders their weld spots rather than make them measure parts to find them.
  • The cell also has greatly reduced the company's cost of manufacturing. When Fode and his team did their initial investigation, they determined that the laser would save them a significant amount per machine in labor and other shop time costs. It was just an educated guess, but it turned out much better in the end.

    "We really can't estimate the amount of savings in the build process that the laser-brake combo has given us because we now have total machines designed with that in mind that we wouldn't have even been able to do without those pieces of equipment," Fode says. "We definitely know that our original estimate is pretty weak sauce compared to what we're really making off of that thing now.

    "This machine can build the part so incredibly fast that it's almost stupid not to go that route," he says. "We determined that for a lot of the parts we were building [before], we could actually cut them on a laser, with the features in them, faster than a sawyer could pull the raw steel off the rack. That's where your savings is."MM

    By Lincoln Brunner, from the April 2006 issue of Modern Metals.

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